芒属部分类群花粉形态观察研究

芒属植物因其拥有适宜作为新一代能源植物开发利用的巨大潜力而广受关注。为了积累中国芒属植物孢粉学研究的资料,本研究利用光学显微镜和扫描电子显微镜对芒属的芒(Miscanthus sinensis)、五节芒(M. floridulus)、荻(M. sacchariflorus)、南荻(M. lutarioriparius)、尼泊尔芒(M. nepalensis)、双药芒(M. nudipes)等类群的共39份材料的花粉进行了观察。结果表明,芒属植物花粉的表面纹饰呈2种类型:颗粒状突起与疣状突起。根据突起程度不同,疣状突起又可分为3种亚类型:不明显疣状突起、疣状突起和明显疣状突起。芒、五节芒、荻、南荻的花粉形态相似性高,表明它们之间的亲缘关系密切。尼泊尔芒和双药芒的花粉形态与芒属其他类群的差异较明显,研究结果支持将它们从芒属中分离出来成立另一个属,即本研究支持双药芒属(Diandranthus)成立。本研究同时表明五节芒比芒演化水平高。为了从孢粉学角度探讨芒属各分类类群之间的亲缘及演化关系,进一步开展花粉外壁的内部结构研究也许是非常有必要的。

Observations and study on the pollen morphology of some taxa of Miscanthus (Poaceae)

Miscanthus (Gramineae, Poaceae) has recently received comprehensive attention because of its great potential to be developed and utilized as a new renewable energy plant. To accumulate information about pollen morphology of Miscanthus in China for relevant study, the pollen morphology of 39 accessions from Miscanthus sinensis, M. floridulus, M. sacchariflorus, M. lutarioriparius, M. nepalensis, and M. nudipes were observed using light and scanning electron microscopy. The exine sculpture of pollen grains of Miscanthus was of two types: granulate and verrucate. The latter could be divided into three types: obscurely verrucate, verrucate, and obviously verrucate based on differences of the raised extent of verrucation. There were distinct differences in the exine ornamentation and pollen size between the group containing M. nepalensis and M. nudipes and the group consisting of M. sinensis, M. floridulus, M. sacchariflorus, and M. lutarioriparius, supporting the separation of M. nepalensis and M. nudipes from Miscanthus as a standalone genus, Diandranthus. M. sinensis, M. floridulus, M. sacchariflorus, and M. lutarioriparius shared a high similarity in pollen morphology, showing the close affinity between them. Meanwhile, M. floridulus was more advanced than M. sinensis in evolutionary history. Nevertheless, it may be essential to further investigate the exine structure of pollen grains of Miscanthus in order to clarify the phylogenetic relationship and evolutionary level between the taxa of Miscanthus based on pollen morphology.